Perch for bird feeder

ABSTRACT

A cantilever perch for a bird feeder is made from a thin strip or ribbon of springy material, such as a stainless steel. Being convex in cross section, the perch is inherently rigid and able to bear load and remain straight. When over-loaded however, as by a large bird or rodent, the perch suddenly flattens, kinks or buckles in a narrow zone across its width causing the cantilever portion to bend sharply with a snap. The unwanted intruder experiences a sudden and terrifying free-fall to the ground. Now unloaded, the perch automatically snaps back to its original straight rigid shape without damage.

This is a division of application Ser. No. 13/815,578 as required by office restriction notice of Mar. 2, 2015.

FIELD OF THE INVENTION

The present invention is in the field of bird feeders and more particularly directed at the perch of a bird feeder.

BACKGROUND OF THE INVENTION

Song bird feeders often have some means of preventing larger creatures (birds, rodents) from feeding. Present bird feeders use complex and expensive spring-loaded sliding closures, twisting perches and the like.

The instant perch cantilevers out from below the seed access holes of the feeder. It is made from a convex strip or ribbon of thin springy material which renders it inherently straight and stiff and able to support load without bending. However, above a certain load limit the strip suddenly buckles or kinks in a narrow zone across its width and becomes substantially non-load bearing and so bends sharply with a snap action. This causes the unwanted load (i.e., a squirrel) to fall whereafter the perch snaps back to being straight and rigid.

SUMMARY OF THE INVENTION

The instant perch is a thin, straight strip of material having a constant convex cross-section along its length. The preferred material is stainless steel which is resistant to rusting and to animal attack.

In its manufacture a thin, flat strip of stainless steel is continuously drawn at high temperature through a die with the appropriate cross-sectional shape. The result is a straight, convex shaped strip. Further processing results in it having the properties of a spring.

The convex (curved cross-section) makes the instant perch inherently straight, rigid and able to bear much higher loads without deflection than the original flat material. This is because, in cross-section, the convex strip forms a beam with an operational thickness that includes the height of the convex shape which is, of course, many times greater that the thickness of the material.

Such a beam is unique in that it remains straight up to the maximum load. The instant it is overloaded it immediately buckles or kinks and bends with a snap. When the excess load has fallen off, it snaps back straight and rigid.

This buckling-straightening can take place repeatedly without damage as can be witnessed with carpenter-type tape measures which uses a similar springy convex strip.

In this way a heavier, unwanted creature will experience a sudden loss of support resulting in, one imagines, a terrifying and uncontrolled free-fall to the ground. Such possibly dangerous failure to gain secure footing on the instant perch soon ends further attempts. This is different from the prior art where the perches remain accessible and so the rodent can safely make repeated attempts to occupy the feeder and work at damaging or destroying it to gain access to its seed supply.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective of the cantilever perch in its normal state;

FIG. 2 shows the same perch in its buckled, kinked and bent state;

FIG. 3 shows a view from the bottom of a reservoir-style bird feeder with one double ended perch having each end cantilevered below the two opposing feeding holes;

FIG. 4 shows a perspective of how four perches can be provided by two convex strips crossing at the mid point whereat they are secured to the feeder.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, in FIG. 3 bird feeder A has seed reservoir B and feed holes C. Perch 1 is a convex strip of thin, springy material, such as stainless steel. The convex radius is constant along its length. The perch has a mounting portion 2 and an cantilevered portion 4. It is straight and stiff but, when overloaded, will suddenly kink or buckle as shown in FIG. 2 and indicated at zone of buckling 3. At the zone of buckling 3 the convex shape effectively flattens to strip thickness which is now greatly overloaded causing it to instantly bend with a snap.

The cantilevered outboard portion 4 may be shaped so as to have a pleasant rounded and/or tapered end as shown at 7.

Strip material 2 can have different specification as to width, length, thickness, and radius of curvature of the convex shape. These variables allow the perch design to have the appropriate stiffness so as to operate as required. in different bird feeders. For example perch 1 may be tapered and/or have drainage holes along the length (not shown) which can affect stiffness. The mounting portion 2 of perch 1 may slide it into prepared sockets in the feeder (not shown).

In FIG. 2 perch 1 is shown buckled from excess weight or load which it is unable to support. Upon removal of the excess weight, and because of the inherent property of such a convex spring strip, perch 1 snaps back to its original straight form without kinking or creasing or loosing rigidity or suffering any damage.

FIG. 3 shows how perch 1 may be installed on a typical bird feeder. Looking up from under the feeder, this embodiment of perch 1 is double-ended with a central mounting hole 5 by which it is fastened to the feeder bottom. Supporting washer(s) of different diameters may be used effect a longer mounting portion 2 to add to the stiffness of the cantilever portion 4. In this embodiment a single perch 1 and single mounting hole 5 serves the two opposite feed holes C.

In FIGS. 1-3 perch 1 is shown with its concave surface facing up where it is most effective, but its is understood that it could be flipped over to have the convex surface facing up however, this results in different kinking properties. Perch 1 may be made from various springy metals such as steel, stainless steel, bronze or from springy plastics such as polycarbonate. The plain curve convex shape shown in FIGS. 1-3 may include other design features such as longitudinal ridges without detracting from the function or scope of the invention.

As shown in FIG. 4 using aligned mid-point mounting holes 5, several perches 1 may be co-attached with a common fastener (not shown) between retaining washers 6 to accommodate multiple bird feed holes C. Washers 6 may be of different diameters. The diameter of the lower perch supporting washer will affect where the zone of buckling 3 occurs. The mounting portion of the instant perch may be annealed such that it can be flatted or otherwise reshaped to more easily work with different bird feeder designs. 

I claim:
 1. A perch for a bird feeder comprising a cantilevered straight and convex strip of springy material, material. the strip having at least one cantilever portion and an attachment portion; the convex having a single radius at least along the cantilever portion.
 2. The perch of claim 1 having two cantilevered portions and where the attachment portion is located therebetween. where at least a portion of the convex strip has a longitudinally extending constant radius of curvature.
 3. The perch of claim 1 where the springy material is stainless steel. A perch for a bird feeder comprising a convex strip of springy material having central and end portions and where the end portions are cantilevered from the central portion.
 4. The perch of claims 1, 2 and 3 where the springy material is steel.
 5. The perch of claim 4 where the steel is stainless steel. 